Electric Vehicle vs Gas Car Savings Calculator

Switching from a gasoline car to an electric vehicle (EV) can save thousands of dollars and significantly reduce your CO2 emissions. How much of either depends on your driving habits, local fuel prices, and how your electricity is generated.

Fuel Cost Comparison Gas car annual fuel cost = (Miles driven ÷ MPG) × Gas price per gallon

EV annual fuel cost = (Miles driven ÷ Miles per kWh) × Electricity price per kWh

The annual savings is simply the gas cost minus the EV cost. Over multiple years, this compounds into a substantial amount.

Real-World Efficiency Reference Values

• A typical gas car achieves 25–30 MPG (miles per gallon)
• A fuel-efficient gas car might reach 40 MPG
• The Tesla Model 3 achieves about 3.5 miles/kWh
• The Chevy Bolt achieves around 3.5 miles/kWh
• Larger EVs like the Tesla Model X average closer to 2.5 miles/kWh
• Average US residential electricity price is around $0.16-0.17/kWh (2024-2025); check your bill, rates vary a lot by state
• Average US gas price varies widely but is often $3.00–$4.50/gallon

CO2 Emissions Comparison Burning one gallon of gasoline releases approximately 8.89 kg of CO2. So the gas car’s annual CO2 is: CO2 (kg) = (Miles ÷ MPG) × 8.89

For an EV, the emissions depend on your electricity grid’s carbon intensity. The US average grid produces about 0.386 kg of CO2 per kWh. So: EV CO2 (kg) = (Miles ÷ Miles per kWh) × 0.386

Even accounting for grid emissions, the average EV produces 50–70% less CO2 than the average gasoline car. In states with high renewable energy (like California or Washington), the EV advantage is even greater.

Multi-Year Savings Total fuel savings over N years = Annual savings × N years. This does not account for purchase price difference, maintenance savings (EVs have fewer moving parts and no oil changes), or battery degradation. Those factors generally favor the EV further.

Grid intensity is the variable that actually matters for CO2

The 0.386 kg/kWh above is the US average, and averages hide an enormous spread. A coal-heavy grid runs near 0.82 kg/kWh and a hydro or nuclear one near 0.09. The optional grid box lets you use your own figure, and the difference between the extremes is bigger than the difference between an EV and a gas car.

Worth knowing: on the dirtiest grids an EV at 3.5 miles/kWh emits about 234 g CO2 per mile, which beats a 28 MPG sedan at 317 g but loses to a 48 MPG hybrid at 185 g. Everywhere else the EV wins outright. If you want the per-mile version of this comparison across vehicle types, the CO2 per mile calculator on this site does it directly and uses the same emissions factors.

Worked Example 15,000 miles/year, gas at $3.50/gallon, 28 MPG gas car vs EV at 3.5 miles/kWh at $0.13/kWh over 5 years. That electricity price is on the low side now; $0.16 to $0.17 is closer to the 2025 US average, and the example is kept as-is so the arithmetic below stays checkable.

• Gas annual cost: 15,000 ÷ 28 × $3.50 = $1,875/year
• EV annual cost: 15,000 ÷ 3.5 × $0.13 = $557/year
• Annual savings: $1,318, so $6,589 over 5 years
• Gas CO2/year: (15,000 ÷ 28) × 8.89 = 4,762 kg = 4.76 tonnes
• EV CO2/year: (15,000 ÷ 3.5) × 0.386 = 1,654 kg = 1.65 tonnes
• Annual CO2 saved: 3.11 tonnes